Technical Field
This invention relates to an image pickup apparatus and a processing method for a result of image pickup and can be applied, for example, to an image pickup apparatus for which a CMOS solid-state image pickup element is used. The present invention makes it possible to further enhance the picture quality in comparison with conventionally available picture quality in regard to control of the exposure time by means of an electronic shutter by dividing a screen image into a plurality of blocks, performing motion detection and controlling the exposure time for each of the blocks.
Background Art
Conventionally, an image pickup apparatus is configured such that the charge accumulation time of an image pickup element is controlled by an electronic shutter to control the exposure time so that, also in a case when an image of an image pickup object which is moving quickly is picked up, an image pickup result having no image shake can be acquired. Regarding such control by an electronic shutter as just described, a method is proposed, for example, in Japanese Patent Laid-open No. Hei 6-165047 and Japanese Patent Laid-open No. Hei 6-261256 wherein a motion of an image pickup object is detected by a system controller and the exposure time is controlled based on the motion detection result together with execution of gain control of AGC (Auto Gain Control) and control by ALC (Auto Light Control).
However, conventional control of the exposure time by an electronic shutter is performed such that, where the exposure time is varied equally for all of pixels which form one screen image to vary the exposure time based on a motion of a portion of the screen image, the exposure time is reduced also regarding a stationary portion of the screen image such as a background or the like. Therefore, in such a case as just described, there is a problem that the S/N ratio at such a stationary portion as just described deteriorates and the picture quality deteriorates as much.
Conversely, there is another case wherein any motion cannot be detected in regard to a small object. In this case, since it is difficult to control the exposure time appropriately, an image of the small object is picked up in a blurred state. Therefore, also in this instance, there is a problem that the picture quality deteriorates.